Subject: Re: [PATCH] reset cached ident date before creating objects

From: Junio C Hamano <[email-masked]>
Date: Mon, 01 Aug 2016 10:58:47 -0700

Junio C Hamano <[email-masked]> writes:

> Jeff King <[email-masked]> writes:
>
>>> So maybe we would have to put reset_ident_date() at the end of the
>>> function instead, at least after git_committer_info() is called.
>>
>> Yes, although "reset and end" still feels a bit weird to me.
>>
>> I'd almost prefer to just have long-running programs insert resets at
>> strategic points.
>
> Certainly "reset at the end" feels weird but it can be explained as
> "for a one-shot thing we use the first time of the default date and
> it gives a consistent timestamp; conceptually, things that make
> multiple commits are like doing that one-shot thing multiple times
> in a row."
>
> When viewed that way, it is not _too_ bad, I would guess.

An interdiff to what we queued previously would look like this:

 builtin/tag.c | 11 ++++++++++-
 commit.c      | 15 ++++++++++++---
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/builtin/tag.c b/builtin/tag.c
index 5dccae3..e852ded 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -225,7 +225,6 @@ static void create_tag(const unsigned char *object, const char *tag,
 	if (type <= OBJ_NONE)
 	    die(_("bad object type."));
 
-	reset_ident_date();
 	header_len = snprintf(header_buf, sizeof(header_buf),
 			  "object %s\n"
 			  "type %s\n"
@@ -287,6 +286,16 @@ static void create_tag(const unsigned char *object, const char *tag,
 		unlink_or_warn(path);
 		free(path);
 	}
+
+	/*
+	 * Reset the default timestamp for the next call to create tag/commit
+	 * object, so that they get their own fresh timestamp.
+	 *
+	 * NOTE NOTE NOTE! if you are libifying this function later by
+	 * turning exit/die in the above code to return an error, be
+	 * sure to jump here to make this call happen.
+	 */
+	reset_ident_date();
 }
 
 struct msg_arg {
diff --git a/commit.c b/commit.c
index b02f3c4..db24013 100644
--- a/commit.c
+++ b/commit.c
@@ -1543,7 +1543,6 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	}
 
 	/* Person/date information */
-	reset_ident_date();
 	if (!author)
 		author = git_author_info(IDENT_STRICT);
 	strbuf_addf(&buffer, "author %s\n", author);
@@ -1564,11 +1563,21 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	if (encoding_is_utf8 && !verify_utf8(&buffer))
 		fprintf(stderr, commit_utf8_warn);
 
-	if (sign_commit && do_sign_commit(&buffer, sign_commit))
-		return -1;
+	if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
+		result = -1;
+		goto out;
+	}
 
 	result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
+
+out:
 	strbuf_release(&buffer);
+
+	/*
+	 * Reset the default timestamp for the next call to create tag/commit
+	 * object, so that they get their own fresh timestamp.
+	 */
+	reset_ident_date();
 	return result;
 }